Sealing a house against insects means closing real entry routes without blocking ventilation, drainage, or building joints that need to function. Start with doors, windows, and utility penetrations where activity is seen. Combining exclusion with sanitation and moisture control works better than filling every gap at random.
Start with doors and windows
Replace damaged weatherstripping, adjust door sweeps, and repair torn screens. A door that shows daylight underneath can also admit many small insects.
Seal utility penetrations with appropriate materials
Gaps around pipes, cables, air-conditioning lines, and ducts are common routes. The material must suit movement, moisture, and fire requirements; do not pack around hot components without knowing the appropriate product.
Do not block required drains or vents
Window weep holes, roof vents, combustion-air openings, and other penetrations serve a purpose. Use screens or purpose-made guards where appropriate rather than sealant that blocks water or airflow.
Reduce indoor attractants at the same time
Sealing entry points does not remove an indoor source such as food, moisture, or an infested plant. Combine exclusion with sanitation and then see whether activity drops before expanding the work.
Sources
- U.S. Environmental Protection Agency — Integrated Pest Management Principles — Integrated pest management emphasizing prevention, exclusion, sanitation, and lower-risk control.